title: Butorphanol prevents morphine-induced pruritus without increasing pain and other side effects: a systematic review of randomized controlled trials.
abstract: OBJECTIVE
  Pruritus is a frequent adverse event after administration of morphine. Butorphanol has been used to prevent morphine-induced pruritus, but its efficacy is still controversial. The aim of this systematic review was to evaluate the efficacy of using butorphanol to prevent morphine-induced pruritus.
  
  
  METHODS
  We searched PubMed, Cochrane Library, EMBASE, and China's BioMedical Disc for full reports of randomized controlled trials that compared the use of butorphanol with either placebo or no treatment for preventing morphine-induced pruritus. The number of patients experiencing pruritus or other side effects was analyzed using relative risk (RR) with 95% confidence intervals (CI).
  
  
  RESULTS
  Sixteen trials (795 patients) were analyzed. Continuous intravenous and epidural butorphanol reduced pruritus with RR 0.22 (95% CI 0.10 to 0.45) and RR 0.24 (95% CI 0.16 to 0.36), respectively. Use of epidural butorphanol decreased the number of patients requesting rescue treatment for pruritus (RR 0.57; 95% CI 0.41 to 0.81). Butorphanol decreased postoperative pain intensity at four, eight, and 12 hr with standardized mean differences of -0.29 (95% CI -0.52 to -0.05), -0.30 (95% CI -0.56 to -0.04), and -0.23 (95% CI -0.46 to -0.01), respectively. Epidural but not intravenous butorphanol reduced postoperative nausea and vomiting (PONV) (RR 0.35; 95% CI 0.19 to 0.66). Butorphanol did not increase respiratory depression (RR 0.71; 95% CI 0.31 to 1.63), somnolence (RR 0.71; 95% CI 0.22 to 2.37), or dizziness (RR 2.45; 95% CI 0.35 to 17.14).
  
  
  CONCLUSIONS
  Butorphanol administered with morphine may be an effective strategy for preventing morphine-induced pruritus as it decreases pain intensity and PONV without increasing other side effects. Thus, it can be recommended for preventing morphine-induced pruritus during the perioperative period.
authors.affiliation: Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, 415 Fengyang Road, Shanghai, PR China.
authors.forename: Bo-Xiang
authors.initials: BX
authors.lastname: Du
authors.forename: Zhe-Ming
authors.initials: ZM
authors.lastname: Song
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: Feng-Ying
authors.initials: FY
authors.lastname: Xu
authors.forename: Zui
authors.initials: Z
authors.lastname: Zou
authors.forename: Xue-Yin
authors.initials: XY
authors.lastname: Shi
mesh_terms: D000701:Analgesics, Opioid / Q000009:adverse effects / Q000627:therapeutic use; D002077:Butorphanol / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D007262:Infusions, Intravenous; D007268:Injections, Epidural; D009020:Morphine / Q000009:adverse effects* / Q000627:therapeutic use; D009292:Narcotic Antagonists / Q000008:administration & dosage / Q000627:therapeutic use; D010146:Pain / Q000188:drug therapy; D020250:Postoperative Nausea and Vomiting / Q000517:prevention & control; D011537:Pruritus / Q000139:chemically induced / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic
chemical_list: D000701:Analgesics, Opioid; D009292:Narcotic Antagonists; D009020:Morphine; D002077:Butorphanol